[0001] The present invention relates to a new derivative of 3(2H)-pyridazinone, acaricidal
and insecticidal compostions containing it and the use thereof for controlling acari,
insects, ticks, etc.
[0002] In particular, the invention relates to a new substituted pyridazinone exhibiting
an increased efficacy in controlling particularly acari and insects which are noxious
in the agrarian, civil and zootechnical fields.
[0003] 3 (2H) -Pyridazinones having fungicidal, insecticidal, acaricidal and/or nematocidal
activity are described, e.g., in EP-A-88384, 134439, 183212, 199281, 232825, 283271,
302346, 320733 and in DE-A-3733220.
[0004] The mentioned DE-A describes compounds of general formula (A):
wherein Ra represents H or a C
1-C
6 alkyl group (optionally substituted with halogen or CH), Rb represents H, alkyl or
halogen, Y represents 0 or S, and Rc is an optionally substituted C
1-C
20 alkyl group. Among the possible substituents of the C
1-C
20 alkyl group there are mentioned C
3-C
8 cycloalkyl groups, optionally substituted with OH or C
1-C
4 alkyl- carbonyloxy groups.
[0005] EP-A-0 377 892 discloses substituted compounds of general formula
wherein R
1 represents a C
1-C
8 alkyl group, R
2 represents hydrogen or a C
1-C
4 group, X represents halogen, W represents oxygen or sulfur and Z is, for example,
a C
sor C
6 cycloalkyl group, optionally substituted e.g. by halogen, C
1-C
10 alkyl groups, C
1-C
S alkoxy groups or C
2-C
S alkoxyalkyl groups.
[0006] The present invention provides a pyridazone derivative, 2-tert-butyl-4-chloro-5-(4-isobutoxymethylcyclohexyl)-methylthio-3(2H)-pyridazinone
(compound I), having higher acaricidal or insecticidal activity than the compounds
of the prior art. Compound I is endowed with a high acaricidal and insecticidal activity
towards acari and noxious insects in the agrarian, civil and zootechnical fields;
in particular it exerts its action against important species of tetranids, hemiptera,
lepidopters, coleopters, dipterans, blattodeas and ixodids
[0007] Compound (I) may be prepared, e.g., by reacting 2-tert-butyl-4-chloro-5-mercapto-3(2H)-pyridazinone
and (4-iso- butoxymethylcyclohexyl)methyl bromide.
[0008] The reaction is preferably conducted in an inert organic solvent (such as benzene,
toluene, acetone, methylethylketone, acetonitrile, dioxane, N,N-dimethylformamide,
dimethylsulphoxide etc.) and in the presence of an inorganic base (such as sodium
hydride, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate
etc.) or in the presence of an organic base (such as triethylamine, pyridine etc.).
The reaction temperature usually ranges from room temperature to the boiling temperature
of the solvent employed in the reaction.
[0009] Compounds such as 2-tert-butyl-4-chloro-5-mercapto-3(2H)-pyridazinone are described
in the literature and may be prepared according to the procedure described, e.g.,
in "Advances in Heterocyclic Chemistry" vol. 9, pages 235-236 and 249-258, Ed. A.R.
Katritzky, A.J. Boultin, Academic press, New York and London 1968, and the literature
referred to therein.
[0010] (4-Isobutoxymethyl-cyclohexyl)methyl bromide can be prepared according to usual methods
of organic chemistry.
[0011] Compound (I) can be in the form of mixtures of isomers, the separation of which can
be carried out by using known chemical techniques such as column chromatography or
thin layer chromatography
[0012] The isolation and use of each individual isomer, as well as the direct use of the
mixtures obtainable from the preparation of compound (I) and the utilization of the
mixtures resulting from an incomplete separation of the isomers are all within the
scope of the present invention.
[0013] As mentioned above, compound (I) is endowed with a high insecticidal and, in particular,
acaricidal activity which is exerted, in general, at all stages of the life cycle
of acari and insects (larvae, adults and eggs); furthermore they possess an excellent
residual activity.
[0014] Thanks to their favourable properties, the compound (I) is suited for use in the
protection of both agrarian and horticultural cultures, environments with human beings,
as well as domestic animals and cattle, from acari and noxious insects.
[0015] For their use in practice, both in agriculture and in other sectors, it is advantageous
to employ the compound of the invention in the form of suitable compositions.
[0016] These compositions generally contain, besides compound (I) as active ingredient,
solid inert carriers (e.g. kaolin, silica, talc, attapulgite, bentonite, diatomaceous
earth, etc.) or inert liquid carriers (e.g. organic solvents, vegetable or mineral
oils, water, and mixtures thereof) and optionally other additives which are usually
utilized in the formulative sector, such as surfactants, suspending agents, dispersants
and wetting agents.
[0017] For particular applicative requirements or in order to extend the compositions' range
of activity it is possible to add other active ingredients, such as for example other
insecticides and/or acaricides, herbicides, fungicides and/or fertilizers thereto.
[0018] The application doses vary as a function of various factors, such as type and degree
of infestation, type of composition utilized and climatic and environmental factors.
[0019] For practical use in agriculture, doses of compound (I) in the range of from 5 g
to 5 kg per hectare usually provide a satisfactory protection.
[0020] The following examples are given to further illustrate the present invention.
EXAMPLE 1
[0021] Synthesis of 2-tert-butyl-4-chloro-5-(4-isobutoxymethyl-cyclohexyl)methylthio-3(2H)-pyridazinone
[0022] The above compound (cis/trans 13/87 mixture) was prepared as follows: To a suspension
of 0.22 g of potassium carbonate in 5 ml of dimethylformamide 0.4 g of (4-isobutoxymethyl-cyclohexyl)methyl
bromide and 0.35 g of 2-tert-butyl-4-chloro-5-mercapto-3 (2H) -pyridazinone were added.
The resulting mixture was stirred for 16 hours at room temperature, then it was diluted
with ether and washed with diluted HCI and brine. After drying the solvent was evaporated
and the resulting crude product was subjected to silica gel chromatography with hexane/ethyl
acetate 9/1 as eluent.
1 H-NMR (60 MHz, CCI4): 8 0.6-2.3 (m, 11 H); 0.85 (d, 6H); 1.55 (s, 9H); 2.85 (m, 2H); 2.9-3.3 (m, 4H);
7.4 (s, 1 H)
[0023] Compound (I) was tested under the conditions described in the following example.
EXAMPLE 2
[0024] Determination of the acaricidal and insecticidal activity
a) Acaricidal activity against Tetranychus urticae (TU.; Acari).
Adults
[0025] Small discs obtained from bean leaves were infested with adult acari and then sprayed
with an aqueous acetone solution (acetone: 10% by volume) of the test compound. The
percentage of deaths was determined 48 hours after the treatment in comparison with
the percentage of deaths of acari which infested discs sprayed only with the aqueous
acetone.
Eggs
[0026] Small discs obtained from bean leaves were infested with acari eggs and then treated
by spraying an aqueous acetone solution of the test compound thereon. The percentage
of non-hatched eggs was evaluated 7 days after the treatment in comparison with the
percentage of eggs which had been treated only with the liquid carrier.
b) Insecticidal activity against adults of Macrosiphum euphorbiae (M.E ; aphides)
[0027] Potatoe plants cultivated in pots were infested with aphide adult females and, after
a few hours, were sprayed with an aqueous acetone suspension (10% by volume of acetone)
of the test compound.
[0028] The mortality percentage of the aphides was determined 24 hours after the treatment
in comparison with the mortality percentage of aphides which infested plants treated
with the liquid carrier only.
[0029] The results of the above tests are reported in Table 1; said results are expressed
as mortality percentage of the acari and insects treated with the test compounds at
the indicated doses.
Claims for the following Contracting State(s) : AT, BE, CH, DE, FR, GB, LI, NL
1. 2-tert-butyl-4-chloro-5-(4-isobutoxymethylcyclohexyl)methylthio-3(2H)-pyridazinone.
2. Composition for controlling acari and/or noxious insect infestations, comprising
the compound of claim 1, one or more solid or liquid vehicles, and, optionally, other
usual additives and/or other active substances and/or fertilizers.
3. Use of the compound of claim 1 as an insecticide and/or acaricide.
Patentansprüche für folgende(n) Vertragsstaat(en) : AT, BE, CH, DE, FR, GB, LI, NL
1. 2-tert-Butyl-4-chlor-5-(4-isobutoxymethylcycohexyl)methylthio-3(2H)-pyridazinon.
2. Zusammensetzung zur Bekämpfung von Befall mit Milben und/oder schädlichen Insekten,
die die Verbindung nach Anspruch 1, einen oder mehrere feste oder flüssige Träger
und gegebenenfalls andere gebräuchliche Additive und/oder andere aktive Substanzen
und/oder Düngemittel umfaßt.
3. Verwendung der Verbindung nach Anspruch 1 als Insektizid und/oder Akarizid.
Revendications pour l'(les) Etat(s) contractant(s) suivant(s) : suivants : AT, BE,
CH, DE, FR, GB, LI, NL
1. 2-Tertiobutyl-4-chloro-5-[(4-isobutoxyméthyl-cyclohexyl)méthylthio]-3(2H)-pyridazinone.
2. Composition destinée à lutter contre les infestations d'acariens et/ou d'insectes
nuisibles, contenant du composé conforme à la revendication 1, un ou plusieurs véhicules
liquides ou solides et, le cas échéant, d'autres adjuvants habituels et/ou d'autres
substances actives et/ou des agents fertilisants.
3. Emploi du composé conforme à la revendication 1, comme insecticide et/ou acaricide.